The purpose of this research study is to determine the long-term safety of rhNGF in treating HIV-associated neuropathy and to allow patients access to rhNGF. Animal studies using this drug have show that it may be effective in preventing further nerve damage or improving existing nerve damage. The study medication has also been tested in healthy human volunteers and neuropathy patients without significant side effects. In a study of 250 patients with diabetic neuropathy, rhNGF was significantly better than placebo in improving nerve function.